Jennifer Lopez and Alex Rodriguez Continue Engagement Celebration on Jet

Jennifer Lopez and Alex Rodriguez are still basking in the glow of their recent engagement ... and the happy couple is taking their celebration to the friendly skies.

J Lo and A-Rod just boarded a private jet together, and it's decked out with tons of cute mementos for their engagement.

J Lo is clearly a big fan of the arrangements ... including powdered donuts crowned with images of diamonds, silver balloons that say "congrats," and a bottle of champagne on ice next to a chalkboard sign commemorating their engagement date. Nice touch!!!

Looks like A-Rod is intent on going over the top in professing his love for J Lo ... they previously celebrated on a bed of roses after the retired MLB superstar dropped to one knee over the weekend for a beachy proposal.